Machine for making glass mounts



Aug. 2,1927. I 9

C. EISLER I MACHINE FOR MAKING GLASS MOUNTS I Filed March 5. 192; 2 sheets-sneer 1 ATTORNEY Aug. 2 1927. 1,637,989

' C. EISLER MACHINE FOR MAKING GLASS MOUNTS I Filed March 5, 1926 2 Sheets-Sheet 2 ATTORNEY I Patented Aug. 2, 1927.

UNITED STATES CHARLES EISLER, or NEWARK, NEW JERSEY.

MACHINE FOR MAKING GLASS MOUNTS.

Application filed March 5, 1926. Serial No. 92,471.

My invention relates to a process for making mounts for radio tubes, incandescent light bulbs, and the like, to the novel resulting product and to the improvement in machines whereby the process may .be automatically carried on.

These mounts when made for tipless bulbs or tubes ordinarily include a'tlared glass tube and an exhaust tube within it, the two being fused together at their ends in the machine. Leading in wires are also fused .into the mass of glass heating the tubes at the same time that the tubes are fused, and in the case of incandescent bulbs it has been common to simultaneously fuse to'the same mass one end of a solid glass rod, known as the cane, forsupporting the anchor wires for the filament.

The machines generally used for this purpose, whether the mounts to be made are for tipless or tipped tubes or bulbs, have a number of heads which are arranged in a circle and are intermittently moved from-one step to another around a circle for the assembling of the parts, their preliminary heating, their final heating and the pressing of them together, the annealing of the mount and the removing of the finished mount from the machine. In machines of this well known character for making mounts suitable for tipless tubes or bulbs, various methods and means have been employed for providing a passage forthe finished mount from one end of the exhaust tube through some part of the mount, so that when the mount is placed in the tube or bulb there will be an open passage through which the tube 'or bulb may be exhausted after the mount is sealed therein. This has been cf- 40 fected sometimes by providing an exhaust tube having a bent end against the inner wall of the stem tube, and forming a hole through'the wall of the stem tube where the end of the exhaust tube is fused, sometimes by placing a mandrel within the exhaust tube and removing it when, or after, the mount is completed and taken from the machine, sometimes by providing a hollow mandrel within the exhaust tube and leaving it in the with such an opening whereby the passage through the 'mount may he certainly and effectively formed and the hole itself uniformly and exactly shaped and located, and whereby the mount is more uniformly strong and more pleasing in appearance than mounts of this type heretofore employed. My invention also includes an improvement in the machine which comprises certain modifications of each of the heads of the machine, this improvement consisting in the provisiouof a suitable mandrel arranged to be longitudinally movable within the exhaust tube, such movement being controlled in time relation with the movement of the pressin g mechanism. The mandrel, which is pref? erably conical in shape, is movable lengthwise of the tube, and I have coordinated the mandrel. with the pressing mechanism in such manner that the mandrel is pushed up ward into the heated zone before the hot glass is subjected to pressure and is moved from the heated zone as the jaws of the press are moved away from the glass and before any substantial cooling of the glass; In this way the time of contact between the mandrel and the united mass of glass is reduced to a minimum both because the movement of the mandrel is initiated promptly and also because of the conical shape of the mandrel. The material of the mandrel should be a metal that is practically nonoxidizable. I have found that a tungsten mandrel gives excellent results.

As the general mechanism of the machine as a whole is not changed by my invention, but only certain details of each of the heads, I do not jllustrate herein the complete machine but will illustrate and describe the invention with reference to a single head.

Referring to the drawings, Fig. 1 illustrates 'in perspective parts of a head embodying my invention and suited for use as a head in a standard mount making machine; Fig. 2 illustrates in a side view, part- ,ly i'nsection,a slight modification where amount which includes an anchor-cane is to be made; Figs. 3, 4 and 5 show diagrammatically the different steps in the operation; Fig. 6 shows a completed mount without an anchor-cane, and Fig. 7 y a mount provided with an anchor-cane. P

Referring first to Fig. 1, 1 represents one of therheads of a standard machine of this general type. This head may or may not be revoluble. 2 are jaws for supporting the flare tube 3, which jaws are carried on the ends of the hinged members 4. The membcrs 4 are drawn towards each other by spring 5 to hold the flare tube between the jaws, but can be separated for the removal or insertion of a flare tube by manipulating the jaws through the instrumentality of the handle 6. 7 indicates generally an attachment for holding the exhaust tube 8. Any suitable clam ing device can be used for this purpose, as or example that of my Patent No. 1,522,001, dated January 6, 192 5, which is the one indicated in Fig. 1 of the present drawings.

9 and 9' are the jaws of the pressing mechanism. They are carried at the end of members 10 which are pivoted at 11 to-the head. Each me her 10 is also pivoted to connect a rod 1 at 13. The jaw 9, Fig.- 2, is ordinarily formed with two set screws 14 having their ends extended beyond the operating face of the jaw but separated to pass on each side of the parts of the mount and engage the face of the opposite jaw 9 thereby fixing the minimum space between the two operating. faces. .The rods 12 are at their ends pivotally connected with the ends of a strap 23, which strap is in turn connected at 24 to a vertically movable rod 25. When this rod is moved upwardly by an suitable means, ordinarily automatically, t e jaws 9 and 9' are brought against the fused glass to form the joint or mass uniting the several parts. 7

. 15 represents a cylindrical block carried by the head 1, and 16 are recesses therein to support leading in wires. Two of these recesses are indicated in Fig. 1, and six are indicated in Figs. 3, 4' and 5, but any number desired may be provided. The lower ends of the flare and the exhaust tube may rest upon the top of this cylindrical member 15.

As thus far described, the head is substantially typical of known heads of mount" machines prior to my present invention. I will now describe the modifications and additions which I have made in accordance with my present invention in order to automatically practice my novel process. 17 is a rod (Fig. 2) extending longitudinally through a passage in the cylindrical block 15 and movable therein. This rod at its upper end is formed as a conical mandrel 17'.

The spring 18 tends to move this rod downward against the bar 19. This bar moves, vertically with the movement of the rods 12 of the pressing mechanism because supported by them by the slotted connections shown. The rod 17 is aligned so that the mandrel 17 can move longitudinall within the bore of the exhaust tube 8. At t e upper limit of the movement of the rod 17 the mandrel extends entirely through the zone where the glass is to be united as a flat- .fused mass of glass.

tened mass. At the lower position of the rod 17 the mandrel is substantially removed downward from this zone. It is to be noted that when the connecting rods 12 move upwardly, upward movement. of the mandrel results and as soon as the jaws begin to separate and the connecting rods move downwardly the spring 18 retracts the mandrel towards its lowest position.

. In the specific embodiment the assembling and the preliminary heating ste s are in no way affected by the features 0 my present invention. In all these machines, however, there is a position at which the final fusing temperature is reached, at the end of which the connecting rods 12 are raised and the jaws of 'the pressing mechanism closed to press together the hot glass of the flare tube and the exhaust tube, with the leading in wires enclosed in the fusedmass. Until the connecting rods are operated the situation is as diagrammed in Fig. 3.- At this time the cone shaped mandrel is at its lowest position at which it has thus far been throughout the operation of the machine.

Fig. 4 'shows the partially made mount turned relatively to the position of Fig. 3 and at a time when the press jaws (not shown) are about closed on the glass, the mandrel being now practically at its top position. Fig. 5 shows the mount in the position shown in Fig. 1, but after the jaws have a ain lowered. Simultaneously with the beginning of the separation of the jaws the mandrel begins to move downward to its normal position shown in Fig. 5 leaving a conical hole 8 longitudinally through the In Figs 31m 5 the leading in wires have been omitted in order 'tobetter illustrate the position of the mandrel.

I have found that if the mandrel is not immediately removed after the hot glass has been taine Even a few seconds are sufiieient to cause the glass to stick to the mandrel and injure the mount, while making the ressed, reliable results cannot be 011-.

walls of the passage rough, or even obliterating the passage and preventing smooth 0 ration of the mandrel when again use in connection with the next mount. While this seems the most essential feature, it also seems necessary, in order to secure uniform and satisfactory operation, that the mandrel should be of a material, as tungsten, which will indefinitely maintain a smooth unoxidized surface. The conical shape of the mandrel is also useful, it being especially important that the extreme upper end of the mandrel should be conical.

Preferably the face of the should be grooved as indicate at 20 so as to produce a thickened rounded wall for the passage extending longitudinally through the mass. This is shown at 21, Fig. 6.

lea ressing jaws Where it is desired to have a cane supporting the anchor wires of an incandescent bulb I shown in Fig. 2. Here the cane 22 iscentrally disposed in a well in the block while the exhaust tube 8 is eccentrically supported within the flare tube. The passage in block 15'for the mandrel rod 17 is likewise eccentrically placed in the block 15.

\Vhile I have described one specific embodiment of my invention in detail my invention is by no: means limited to the particular details thereof, but includes all prefer to make the modification.

modifications as are within the principles of .my invention as herein described and set forth in the appended claim.

Having thus described my invention, what I claim and desire to protect by Letters Patent is: a

In a head for lass-mount making machines of the type in which portions of suitably held inner and outer tubes are heated at adjacent ends and the joint completed by the operation of a pressing mechanism, the combination with the pressing mechanism of a movable mandrel conical at its end to engage the heated interior surface of the inner tube andmeans for'moving the mandrel in time relation with. the pressing mechanism. v

In testlmony whereof, I have signed my name to this specification.

CHARLES EISLER. 

